Add linux-firmware-raspberrypi to image

[metalefty]

This enables Wi-Fi on Raspberry Pi 400.

Fixes:

• https://github.com/AlmaLinux/raspberry-pi/issues/23
• https://bugs.almalinux.org/view.php?id=175

[metalefty]

Still testing with actual devices.

[metalefty]

Ready to merge now.